Why doesn't the world go dark each time we blink? Researchers at
University College London say it's because blinking turns off parts of the
brain so we don't notice the change.

Blinking is difficult to study, but the scientists devised a clever
experiment. They constructed a fiber optic light device that was placed
in the mouth of a subject who wore lightproof goggles. When the device
was turned on, light illuminated the retina of the eye through the roof
of the mouth rather than through the eye! Therefore, the
researchers could keep light on the retina even when a subject's eyes
were closed.

Areas of Reduced
Brain Activity

The scientists used functional magnetic resonance
imaging to scan a subject's brain. When the retina was stimulated
with the fiber optic light, the researchers found that blinking reduced
activity in parts of the visual cortex, parietal cortex and prefrontal
cortex. So, decreases in brain activity occurred even when the retina was
stimulated with light.

These data should help us understand how we get an uninterrupted view of
our surroundings. Life would be dangerous if the world went dark each
time we blinked. Thankfully, our brains have a built-in system to keep
this from happening.

Did you
Know?

We blink 10 to 15 times each minute (more than 5 million times
each year!).